(A-B) Genetically labeled microglia analyzed following MCAO-induced stroke show significant downregulation of microglial markers P2RY12 (A) and TMEM119 (B) in the ischemic core and penumbra. For both (A) and (B), the contralateral control hemisphere is the left column, the stroke-affected ipsilateral hemisphere is the right column. (C–D) Higher magnification of contralateral control area of the striatum, the stroke penumbra and core. P2RY12 and TMEM119 expression is reduced in the penumbra, and almost completely lost in the stroke core. In the stroke core, microglia are larger and amoeboid. (E) The cytokine CXCL10 is significantly upregulated in microglia of the stroke core. Scale bars = 500 µm (A,B), 50 µm (C–E).